Alfriston is a secondary-age day and boarding school for girls in Beaconsfield,

Buckinghamshire. It caters for pupils with a wide range of special educational needs and disabilities between the ages of 11 and 18.

In January 2008 Duggan Morris Architects were commissioned in January 2008 to

consolidate the sports department and to replace an existing redundant swimming pool

structure with a new up to date facility with the ability to open the swimming pool to the public as a revenue generator.

The scheme

The plan arrangement is simple. New swimming pool changing is extended from the side of the existing gym. The pool enclosure extends linearly westwards into the landscape. The site levels have been altered to bring the primary entrance to the sports department central to the pool and gym with a secondary entrance to the rear of the gym. Wide access ways and large storage areas are included to service varying disabilities and mobile hoist equipment. The overall footprint sits neatly within a constrained footprint of greenbelt land (playing fields) to the south and protected trees to the north. The new pool room thus looks out onto the playing fields with unobstructed views.

Intended to be a contemporary expression of the local pitched roof vernacular, the design of the new pool enclosure is articulated by three duplicated pitched and tapered segments, adopting similar proportions to the main school building. This rippling sculptural form also serves as an acoustic baffle thus preventing a high reverberation of sound, which is a crucial aspect of the brief. A 1m high low level glass strip circumnavigates the pool roof thus reinforcing the building component and giving the appearance of and elevated (or levitating) form.

Material and construction

The prefabricated timber structure was manufactured off site by Cowley Timber in 12

triangulated truss modules, the largest being 12m long x 6m high. The components are

constructed from cross laminated European Scandinavian whitewood forming the main

beams, columns and rafters with a laminated ply external skin. The interior face is factory finished in a breathable light white wash. The trusses were delivered with a weather tight membrane ready for roof dressing. The component connections are bespoke invisible steel plates with plugged bolts. The structure is raised off the concrete deck with slim circular posts located at each cranked position terminating at the steel connector plates. The entire site assembly took place over an 8 week period. This method offered precise, high quality finishing with no requirement for temporary internal or external scaffolding as well as cost and programme benefits.

A standing seam roof system with integrated cladding clips supports the Plato timber roof allowing the entire pool roof and perimeter walls to be clad in the same material, with precise spacing and alignment. Thus the entire assembly reads as a simple object form. All rainwater pipes are external but hidden behind the timber rainscreen. The glazed strip is achieved using a self-draining shuffle glazing system with minimal framing components. The cranked cills follow the geometry of the facades above and are powder coated matt black to match the masonry finish.

The interior finishes palette is minimal with the majority of materials self-finished. The overriding interior quality is warm, clear and silent.

The overall ambition was to make sure the structural logic is easily read, but through the simple execution of detail, selection of fittings and finishes retain a practical appearance, free of decoration and unnecessary maintenance.